Turbomachines, such as stationary gas turbines or aircraft engines, are conventionally provided with annular space seals between adjacent guide blade rows and moving blade rows for the purpose of at least reducing a fluid exchange between an annular space through which a main stream flows and cavities situated radially on the inside and outside of the annular space. An annular space seal of this type is shown, for example, in U.S. Pat. No. 3,730,640 A. This known annular space seal has a plurality of slotted elastic sheets, which extend from a rotor web in the axial direction of the turbomachine, downstream from a moving blade row, and thus cover a radially inner cavity in the direction of the annular space. A disadvantage of this annular space seal is that it is situated on the rotor side, whereby it contributes to an increase in the weight of the rotor and affects the moving behavior of the rotor.